Method of and apparatus for pressing materials into molds



Nov. 8, 1932. w. s. MURRAY 1,886,831

METHOD OF AND APPARATUS FOR PRESSING MATERIALS INTO MOLDS Filed May 18, 1929 2 SheetseSheet 1 j gwfaemtoz Nov. 8, 1932. w, s, MURRAY 1,886,831

METHOD OF AND APPARATUS FOR PRESSING MATERIALS INTO MOLDS Filed May 18, 1929 2 Sheets-Sheet 2 awwemto'c IZI ' M the places which would otherwisebe t o Patented Nov. 8, 1932' omrao STATES PATENT. OFFICE.

wnmrm a. mu, or once, mew ronmlnsslenon 'ro ,oimmn corhmmx', Lnnrnn, or comma, NEW roux, a coaronerron or new YORK IE'I'EOD 01' AND APPARATUS FOR PBESSING MATERIALS INTO IOLDS App1icatlon filed lay 18, 1929. Berta! 1%. 884,189.

This invention relates to an improved method of and apparatus for pressing material into molds.

It has been common in the art heretofore 5 to press suitable ductile material, for example, metal, into molds by the use of fluid or liquid under high pressure, which directly against one face of the material to be pressed and thereby forced such material into 10 contact with the inner face of the mold.

Where the object to be formed was a hollowbody, the fluid ressure applied to the interior of such ody served to expand it wherever permitted by the mold, with the re- 15 suit that the expanded portions were thinner than those portions of the hollow body which were not expanded. The resultant article so made was not of uniformor substantially uniform thickness throughout, but was of $9 appreciably different thicknesses. As a re suit, the blank which is to be expanded must have a. "it all hicliness much greater than the wall thiclmess or the finished article at the expanded portions, thus leaving the unexpanded portions unnecessarily thick so that the completed article is unnecessarily heavy and more expensive on account of the cost at the additional metal.

Furthermore, because the blank is thicker m than necessary for the expanded portions of the finished article, much heavier pressures are required at starting to expand the metal. 'lio overcome the foregoing disadvantages, a method has been proposed which consists in gradually expanding the metalof the blank and during the expanding process maintaining a flow of the metal to the expanded portions so as to provide a suficient thickness at i It by e expansion. In car it out this cod, the bl is subjected not only to an internal pressure, capable of expanding it, but also to a separately controlled upsetting to torce,--that is, to a torce which tends to compress the blank and upset it or th cken it at the part being expanded, the upsetting force bein such as to cause a proper flow of the metal into the expanding portion of the his The upsetting force is conveniently acted provided b a plunger which acts on the end of the blanh.

Attempts to practice this method have proved unsuccessful, in the past, for the reason that the blank end receiving the upsetting pressure deforms, collapses or buckles laterally and does not transmit such pressure to the expanding portions of the blank nor provide the desired flow of metal thereto.

It is the object of the presentinvention to elimnate this defect.-

According to the present invention, the

blank, which is usually a hollow body, is sup.-

ported against latera crimping, collapse, or buckling during the application ofthe upsetting force. Such support is advantageously provided over all of the unexpanded portions of the blank receiving the upsetting pressure or compression. The unexpanded portion ot the blank receiving the upsetting pressure, being thus unable to collapse latera y, in necessarily collapse in the direction of the expanding portion of the his and am quently metal from the unexpded portion is caused to flow into the expanding portion.

ile apptus ct difierent ty me be employed for ar-i out the new method, the resent invention includes apparatus par ticarly advantageous tor the pose.

lln the drawings: so

Figures 1-3 inclus1ve,are detail sectional views illustrating the manner of producing an automobile housing in accordance with the invention, Figure 2 being a sectional'view on line 2-2 of Figure l, and Fire 3 similar to Figure 2 and showing a further stage; in the process;

Figure 4 is a diagrammatic view illreting a type of apparatus for practi the invention;

Figures 5-8 inclusive, are detailed views oi the same.

The invention is exemplified in the menutacture of a seamless or weldless housing for automobile axles. Heretofore, such hous 5% bags have been made of two or more arts and then welded together. lin aceor ance with the present invention, a stronr and more reliable housing is made more rapiy and economically by expang a; tube oi m9 suitable materialin a matrix having the roper interior configuration, the expansion eing done by a flui or hydraulic pressure appl ed internally, while at the-same time an upsettin pressure is applied to the ends of the tubu ar-blank to insure a travel or flow of metal into theexpanding portions of the form of die-holding device which has the advantage that the matrix may be quickly opened for the insertion and removal of a blank-and quickly closed. In this, the die-holder has an open base formed of the integral parts 115, 116 and 116 so as to leave an opening through the base to permit the insertion of cross-bars 118, each of which projects, at both ends,-beyond the base, the projecting ends having screw-threaded holes into which are screwed stud bolts 119 having nuts 119 Across the top of the die-holder are placed two upper cross-bars 121, each forked at one end 121 to engage beneath the nut of one stud bolt and laterally slotted at the other end 121 to engage beneath the nut of the other stud bolt of its respective pair of stud bolts. Each upper cross-bar is provided with a pressure screw 124 having a handwheel 124 By screwing this hand-wheel down, the two parts 113 and 114 of the die-holder, which carry the matrix halves 111 and'112,

' are forced into close contact with each other.

When it is desired to open the die-holder and matrix, it is only necessary to turn the handwheel, and swing the upper cross-bars 121 angularly to release their laterally slotted en' s, 121 and then draw their other ends, 121 from beneath the corresponding stud bolt nuts. The matrix parts are attached to the respective parts of the die-holder by screws 47 or otherfasteners.

Figures 4, 5 and 8 show a form of apparatus for applying an internal expanding presnally through openings in two pedestals, 92,

- 93, 92 93 each of the pedestals 92, 92, be-

ing provided with a feather, one of which is indicated at 95 Fig. 5. ,On each screw 86, 86 is mounted a rotatable nut 96, 96 to each of which is-fixed a gear wheel 97, 97.

In the usual practice, the gear wheel is fixed to its nut by a splinewhmh enters cooperating grooves, one in the hub and the other in the'gear-wheel. One of these splines is indicated at 97 Fig. 5.

The inner end of each nut is flanged to bear against the flange of a liner for its corresponding-pedestal 93, 93 one of these liners for the. edestal 93 being indicated at 93 Fi 5. he outer end of each nut is arranged to ear against a ball-bearing device which is located between the said inner end of the nut and the outer pedestal 92, 92 One such ball-bearing device is shown in section at Z in Fig.5. t comprises two bearing rings or washers and an intermediate ball-carrying shown as made integral with a central passage 90. The outer end of the screw 86 is connected by a union 87 with a pipe longitudinally movable through a pedestal head 84 carried on a pedestal 84 a suitable stuffing box being provided for the pipe 85, as will be clear from Fig. 5. The outer end of the pipe 85 slides telescopically in the pipe 83.

The means 'for supplying liquid under pressure to the pipe 83 and for exhausting it from said pipe may take any desired form. In this exemplification, the pipe 83 is supplied with high pressure liquid through a pipe 17 which may receive liquid under pressure from pipe 14, the supply from pipe 14 being controlled by a valve 14 Also the pipe 17 may be supplied with liquid under a regulable and still higher pressure from an intensifier 22 provided with suitable pipe connections and valves which may be of an preferred construction. Inasmuch. as 'suc intensifier forms no part of this invention, it

is not illustrated in detail. The supply to pipe 14 is from pump B. The exhaust from pipe 83 is through a pipe 29 equipped with a valve 29 Pipe 14 may advantageously be provided with a safety valve 18, and the system generally modified and refined in detail.

The gear wheels 97 and 97 are driven simultaneously by the respective pinions 98, 98 fixed on a pinion shaft 99 journaled in suitable bearings carried by the pedestals 93, 93 respectively, as will be clear from Fig. 4. To the pinion shaft 99 is fixed a gear wheel 101 which meshes with a driving pinion 102 fixed on a shaft 104 mounted in suitable bearings 125, 125

The transmission shaft 104 is drivenfrom assess:

a shaft 106, through a two-speed transmission gearing of the usual shifting gear type indicated generally by the reference letter 105 in Fig.

. The power shaft which is mounted in a bearing 106 has fixed to it a worm-wheel 107, by a worm 110 fixed on the motor shaft 109. of asuitable'electric motor indicated'at 108. .This motor is of the reversible type, so that the nuts 96, 96 may be rotated in either direction to permit the screws to be moved longitudinally outward as well asv inward whenever r uired. The screws ca e plungers 88, 88 with their mandrels 9 91 The plun ers are adapted to bear against the ends of t e blank and the mandrels to fit snugly within said ends. Movement of a plunger inward thus supplies the upsetting pressure to the blank. The mandrels provide'the su porting means for preventing the unexpan ed portions, in'

to is the result of several elements, to wit the thinness of the walls of the blank or tube,

which renders them unadaptable for sustaining or transmitting upsetting pressure or compression, and the frictional resistance offered to flow ofthe metal by the contacting surfaces of the die. By supporting the tube internally as wellas externally throughout the entire range of the unexpanded portions receiving the upsetting or compression, such deformation is eliminated.

The manner of practicing the invention in the formation of the seamless housing will be clear from Figures 1, 2 and 3. Figure 1 shows the starting blank 50 which is usually a seamless drawn tube of low carbon steel or iron. This tube 50 is inserted in the matrix and the plungers 88, 88 are brought quickly into contact with the ends of the blankb setting the shift gear mechanism for big speed rotation of the shaft 104 and then starting the motor 108 to run in the proper direction to drive the screws 86, 86 toward each other. The matrix illustrated has an enlarged central part a where expansion is to occur and end parts a which are reduced and fit the exterior of the tube to prevent its expansion and maintain it unexpanded. The mandrels enter the ends of the tube, and, when the plungers contact with the tube ends, but before the application of pressure thereto, the mandrels are internally supporting the tube over their entire portions between their ends and the points where expansion oc'cu-rs. Thus, while'the upsetting forces are a plied to the ends of the tube,the unexpandportions ofthe tube are supported against I lateral collapse or buckl plungers 88, 88 make'or ap roachto contact with the ends of the bl the transmismm at a ower speed proportionate with the rate of expansion and force the plungers slowly against the tube ends, and thereupon the liquid pressure is apphed to the interior of the blank through pipe 83 by opening valve 14 The intensifier 22 may or may not be brought into action'to an out the liquid pressure as desired. The internal ressure expands the blank-at those places w era the inner walls of thematrix are not in contact with the blank. In other words, the blank tends to move into the'recesses of the mold. At this time, there would be a tendency of the blank to become thinner at the expand ing portions. But at the same time the plun ers are forcing the tube ends inwardllys,

there y tending to upset or thicken said we but not actua 1 doing so because of the counteracting e ect of the expansion of the blank,that is, metal is flowing into the ex-' panding portion from the ends receiving compression. The internal and upsetting pressures may be regulated as already described. In this wa the blank, is forced to fill the interior of t e matrix, while, at the same time, the thickness of the wall of the expanded portion is maintained substantially uniform with those of the unexpanded ortions because of the flow of metal thereom. The unexpanded portions are further prevented from collapsing or buckling laterally by the internal supports given thereto by the mandrels. In order to draw the blank to the completed form, it may be necessary to act on it in a series of stages, with different matrices and with annealing between the different stages. For example, Figure 2 represents one stage and Figure 3 a further stage, the latter showinga central portion enlarged to a greater extent than in Figure 2. The process maybe carried out in as many stages as desired. I

When the blank has been expanded in the matrix and the liquid pressure released, plungers 88, 88 may be withdrawn from contact with the blank by reversing motor 108. In order to return the screws and plungers quickly to the starting position, the transmission mechanism may be shifted to the high speed gears. It will be understood that the plungers 88, 88 with their mandrels 91,91 may be replacedby others-of difierent size, according to the nature of the work. For this reason,

ing. When the rs are shifted to drive the shaft 104 each plunger may be screw-threaded into the may have an enlargement or flange bearing 4 on the end'of the screw, as will be clear from 1 Fi re '8.

is application is a continuation in partof my prr application in Serial No. 133,528, filed September 4 1926.

What is claime is: l. The method of expanding a hollow blank of ductile material into contact with the interior wall of a matrix, which in part fits the blank and in part is enlarged to allow the blank to expand therein, which comprises subjecting the interior of the blank to a fluid pressure suificient to expand it radially, while subjecting the metal of the blank to an flowing pressure whereby metal upsetting from the unexpanded portions is supplied to the expanding portions of. the blank, and supporting the walls -of the unexpanded ortions as far as the point of divergence o the expandin portion before and during the subjection 0 said metal to said upsettlng pressure to prevent lateral collapse during application of the upsetting pressure.

2. In combination, means for supplying to the interior of a blank fluid under pressure sufiicient to expand the material of the blank, I a plunger arranged to act against the end of.

the blank and to apply upsetting flowing pressure thereto, and a mandrel associated with the plunger and adapted to enter the blank as far as the point of divergence of the expanding portion, said mandrel. entering the blank before contact of the plunger to sup ort internally the unexpanded portions of t e blank.

In testimony whereof, I have hereunto set my hand.

WILLIAM S. MURRAY. 

